Motor Spins Briefly when Machine is Powered On - Stops Cutting After 5 Minutes

[Brad Wardman]

My problem from a couple weeks ago was resolved with a new Xterm board....This is NEW.
Ran 2 projects (9 hours) after the xboard was changed, all good.

Now, the spindle turns for half a second when the main machine power is turned on (on/off switch on keyboard side of machine). Shut it off & turn it on, does it every time !!

If you continue through the setup, everything spins & runs fine...for about 5 minutes !!! Then, the truck raises, machine stops, and the screen reads to close the cover. I have bypassed the cover switches for testing purposes, and this has not helped.

Ideas appreciated, as we have 2 more awards to cut for a national dog show in March.

Brad

[bergerud]

The motor spinning briefly when you power up or when you close the cover is normal. The machine stopping because it thinks the cover has opened is not normal. This probably indicates a wiring problem. I have heard of the board sensor wire grounding inside the truck as causing the machine to think the cover is open. Check all the wiring and connectors that you have recently disturbed.

[Digitalwoodshop]

Try thumping on the top post on the right side of the keyboard and see if the motor starts again and off.. I have had 3 of 4 machines snap the C1 Capacitor that causes this. One side snapped off... Could be your problem too or another bad component on the X Termination Board.

Please be sure and not bypass your right side cut motor safety cover switch as with this condition the cut motor could start on it's own while changing bits.

I would call LHR and order another board.

Good Luck,

AL

[bergerud]

But Al, he is getting a close cover message after it stops. The motor stops and the truck goes up. The machine is pausing as if the cover was lifted.

[CNC Carver]

Check the wiring to the left side switch. How did you bypass? Check those connections also.

[badbert]

Part of the problem is the left side switch is actually an input to the controller, like a sensor. And if any other sensor shorts out, that is the first code. Check the FFC ribbon cable. Mine was not inserted squarely, shorted two pins, and I got the same error.

[Digitalwoodshop]

But Al, he is getting a close cover message after it stops. The motor stops and the truck goes up. The machine is pausing as if the cover was lifted.

Yes, got that one totally wrong... Need to lay off the Booze during the day... LOL...

I have 2 strips of masking tape that act as seat belts on the top cover that wrap down into the flex slot. When the cover is closed it holds it tight to the switch and when the cover is lifted it bents up. That might help...

The plug in the back for the left switch can come loose. And the switch screws can come loose as can the screws on the clear cover hinges.

AL

[cestout]

But I don't see how the cover switch relates to the motor spinning when powered on. The only time it should spin like that is when you install the requested bit. My C machine had a marginal cover switch from the get-go. It finally failed totally and I replaced it with one left over from my first A machine (returned to sears long ago). The switch was good but the wire was broken on the A machine harness. I had to remove the solder so the clips could slide on.
Clint

[Brad Wardman]

PROBLEMS SOLVED !!
Found the solutions(s) to my problems...just thought I would update both this and my other thread, in case someone else has these issues.

Initially we had "check cut motor" with the ability to reset the machine and cut another project...this got worse through several projects. After a full check, including motor removal & testing, we thought we would try a new x-Term board, as it seemed a good possibility and I wasnt getting consistant readings from it on my multimeter. Replaced with a new board (also ordered all new parts from Digikey to rebuild the other one). Motor ran about 2 minutes before a loud POP and obvious smell of burning electrical components !! The new xterm board had been fried (quite literally).

Waited a day and had my parts to completely rebuild the Xterm. Upon reassembly, the "check cut motor" error returned. Disassembly of the motor at this time showed that one of the motor brushes had a broken wire (that runs inside of the little brush spring). This was repaired and two projects were cut without issue.

Then, upon starting the 3rd project, we get the "close cover" error. What a Week !!! So, bad or dusty switch probably...so I remove & disassemble & clean the cover switches. Test them on a meter and all are working good. Put them back in...."COVER ERROR" !! So, to hell with it all....I bypass both switches because I have to get this last project cut for an order. Project runs to about 35%...then "COVER ERROR"...What ???

So, a ground issue ?? Take everything apart...again. Cover, bottom plate, xterm, motor...everything. Follow all the wires around the whole machine and I FIND THE PROBLEM !! One of the wires that run to the cover (comes up the back tube by the motor) has a single strand of wire protruding from the lower side of the plug...down in the little hole. This was grounding out. Redid the wire in the plug...All fixed. All good so far !!

Anyway, I dont know if that tiny wire caused the initial & followup xterm problems & brush issue....or if everything was coincidently independant, but its here, for the record, for anyone else who has issues.

Thanks all for your help & input.
Brad